This invention relates to an apparatus and method for evaluation of suspension systems, particularly those of automobiles. More specifically, the invention is directed to evaluating the in situ performance of the shock absorbers, important components of automotive suspensions.
Known devices for testing shock absorbers requires their removal from the vehicle. This practice is highly impractical for two reasons. First, labor costs involved in the shock absorber's removal for testing and subsequent reinstallation are prohibitive, in that such costs may be equal to or greater than the cost of replacement shock absorbers. This is particularly true with shock absorbers founded in MacPherson-type suspensions (i.e., MacPherson struts) wherein removal of the shock absorber necessitates the disassembly of other suspension components, such as the spring, balljoint and brake assembly. Second, testing of a shock absorber isolated from its operating environment is believed to be unsatisfactory as its dampening ability is measured against an arbitrary standard rather than relative to the suspension system of which it is a part. As the performance of the shock absorber in conjunction with the rest of the suspension system affects the handling, ride, suspension performance, stability and safety of the vehicle, the practice of shock absorber testing as an isolated component can be seen to be unsatisfactory.
Other devices currently on the market, namely those operating on the seismograph principal do evaluate the suspension systems as a whole, but are restricted to record movement of the vehicle's body withoout allowing the deduction of the dampening factor of the system, (i.e., shock absorber performance).
The present invention overcomes the above described disadvantages by providing an apparatus and method for the evaluation of a shock absorber without removing it from its operating environment, i.e., without removing it from the vehicle.
Another prior art system is disclosed in my Belgian Pat. No. 35112, which will be discussed hereinbelow.